let d = new Date()
let w = d.getDay()
switch (w) {
    case 0:
        console.log('星期日')
        break
    case 1:
        console.log('星期一')
        break
    case 2:
        console.log('星期二')
        break
    case 3:
        console.log('星期三')
        break
    case 4:
        console.log('星期四')
        break
    case 5:
        console.log('星期五')
        break
    default:
        console.log('星期六')
        break
}
